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Measurement and data analysis methods for field‐scale wind erosion studies and model validation
Author(s) -
Zobeck Ted M.,
Sterk Geert,
Funk Roger,
Rajot Jean Louis,
Stout John E.,
Van Pelt R. Scott
Publication year - 2003
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.1033
Subject(s) - aeolian processes , fetch , environmental science , erosion , sediment transport , wind speed , scale (ratio) , deposition (geology) , geology , sediment , hydrology (agriculture) , geotechnical engineering , geomorphology , geography , oceanography , cartography
Abstract Accurate and reliable methods of measuring windblown sediment are needed to conrm, validate, and improve erosion models, assess the intensity of aeolian processes and related damage, determine the source of pollutants, and for other applications. This paper outlines important principles to consider in conducting eld‐scale wind erosion studies and proposes strategies of eld data collection for use in model validation and development. Detailed discussions include consideration of eld characteristics, sediment sampling, and meteorological stations. The eld shape used in eld‐scale wind erosion research is generally a matter of preference and in many studies may not have practical signicance. Maintaining a clear non‐erodible boundary is necessary to accurately determine erosion fetch distance. A eld length of about 300 m may be needed in many situations to approach transport capacity for saltation ux in bare agricultural elds. Field surface conditions affect the wind prole and other processes such as sediment emission, transport, and deposition and soil erodibility. Knowledge of the temporal variation in surface conditions is necessary to understand aeolian processes. Temporal soil properties that impact aeolian processes include surface roughness, dry aggregate size distribution, dry aggregate stability, and crust characteristics. Use of a portable 2 tall anemometer tower should be considered to quantify variability of friction velocity and aerodynamic roughness caused by surface conditions in eld‐scale studies. The types of samplers used for sampling aeolian sediment will vary depending upon the type of sediment to be measured. The Big Spring Number Eight (BSNE) and Modied Wilson and Cooke (MWAC) samplers appear to be the most popular for eld studies of saltation. Suspension ux may be measured with commercially available instruments after modications are made to ensure isokinetic conditions at high wind speeds. Meteorological measurements should include wind speed and direction, air temperature, solar radiation, relative humidity, rain amount, soil temperature and moisture. Careful consideration of the climatic, sediment, and soil surface characteristics observed in future eld‐scale wind erosion studies will ensure maximum use of the data collected. Copyright © 2003 John Wiley & Sons, Ltd.